Exogenous Methyl Salicylate treatment increases tomato zingiberene levels and decreases infestation of adult whiteflies and red spider mites

Phytosanitary management on tomato crop is a challenge for organic and conventional growers. Whitefly Bemisia tabaci (Gennadius) and mite Tetranychus evansi Baker and Pritchard are among the major pests. Methyl-salicylate (MeSa) is a methyl ester from salicylic acid and activates secondary metabolism pathways in plants. Zingiberene (ZGB) is a secondary compound associated with resistance to B. tabaci. The aim of the study was to study the relationship between the exogenous MeSA spraying and zingiberene content in tomato leaves and adult whitefly and mite responses. MeSa concentrations [0 (control), 100, 200, 300, 400, 500 µg L−1)] were applied on tomato to evaluate the ZGB content and the relationship with whitefly and spider mite on plants. After the last ZGB analysis, plants were placed in B. tabaci-highly infested greenhouse. The number of adult whiteflies on plants was determined three days later. Tomato leaflets were collected from treated plants and infested with five T. evansi e females. The number of larvae emerging from eggs was evaluated after 96 and 120 h. Reduction of adult whiteflies (from 78 to 8